This invention is concerned with a three dimentional logical toy and in particular with the game puzzle known as "Rubik's Cube," a demonstration device which is said to have forty-three quintillion configurations. Generally, the cube is truncated into twenty-six surface blocks which present six groups of distinguishable faces, or fifty-four exposed faces. The said blocks are moveable relative to each other on the planes of truncation and are secured together on three right angularly related axes X, Y and Z. A feature is the rotatable securement on said axes by means of the center blocks that revolve upon a cross and present interior races on the lines of truncation so as to capture the bearing faces of anchors that project inwardly from the blocks. It is a general object of this invention to provide means by which the blocks in any one plane of truncation can be readily and easily rotated and thereby quickly moved relative to the others on any one of the axes X, Y and Z.
Alignment of the truncations about which movement is to occur is essential in three dimensional logical toys of the type under consideration, otherwise obstruction to rotation will exist and thus hamper expediency in solution of the puzzle. Interiorly, the cube is characterized by a spherical cavity with the aforesaid interior races exposed inwardly so as to be engaged by the bearing faces of the anchors. The spherical cavity is comprised of the inner side portions of the center blocks, the inner edge portions of the edge blocks, and the inner corner portions of the corner blocks. The said inner portions of the blocks are spherically truncated and together form the spherical cavity, when aligned. However, any misalignment of the side of the cube to be rotated will disrupt and/or destroy the said spherical cavity configuration and thereby prevent free turning of that side, and also of the four adjacent sides. Misalignment therefore slows the process of solution, it being an object of this invention to establish alignment as a result of rotating the side or sides of the cube, whereby initial alignment is not required. With the present invention, each moveable block of the cube is cam-shaped at its interfaces with adjoining blocks, as will be described, and accordingly a substantial degree of misalignment can be tolerated while deftly and speedily rotating the sides of the cube for the solution required.
It is an object of this invention to greatly improve operability of the three dimensional logical toy, without changing its fundamental construction as it is presently known in the art, whereby rotation of the cube sides in the groups of nine blocks is not hampered by misalignment, even to a substantial degree. In practice, a reasonably close alignment is all that is necessary, whereupon turning of the side of the cube automatically aligns the nine blocks of the side being rotated with the nine blocks of each of the adjoining four sides. The degree of misalignment which may be tolerated is determined by the extent of the cam configuration, a maximum cam configuration being shown and described.